Patient Safety Comes First in Clinical Trials

Karen E. Woodin, PhD

In This Article

Rules and Procedures

Operating procedures must be established before the DSMC starts reviewing data. Meetings may be held at regular intervals, for instance, every 3 months, or their schedule may be determined by enrollment, such as holding a meeting after enrollment of every 50 patients. It is important to keep everyone informed of the trial progress and to plan meetings well in advance so that all members will be available. Committees may meet in person or they may take advantage of video or teleconferencing, especially when there are issues that need immediate consultation.

Rules must be established concerning which parameters the committee will review, the amount of data to be examined, and how "clean" the data will be before being given to the group. Data cutoff points need to be established for each review period. The DSMC may examine efficacy data as well as safety data, since both may be necessary to make informed risk-versus-benefit decisions.

Communication between the DSMC and the sponsor of the trial is extremely important. The charge of the committee should be clear at the start of the project to avoid conflict later. If possible, stopping rules should be decided in advance of any data collection; this may be feasible when potential risks can be foreseen, either because of the class of drug or the disease condition. It is not possible to establish stopping rules for unforeseen risks; however, there should be clear agreement about how this information will be communicated and who (DSMC or sponsor) will have the final authority to stop a trial or put it on hold until a decision can be made.

A DSMC may occasionally recommend to the sponsor that a study be stopped before the planned enrollment is complete, either because of a safety problem or because patients are doing so well on the new treatment that it would be unethical not to provide all patients with the study drug as soon as possible. The decision to stop a trial early is not an easy one in either of these cases, involving considerable discussion and weighing of both the risks and the potential benefits. In both the case of a potential safety hazard or a potential surpassing benefit, the committee will no doubt request additional data from the sponsor so that all information to help clarify the issues is available to them. They will look at baseline data and demographics, and they will investigate all potential confounding effects to ensure that the problem or benefit is attributable to the treatment rather than to an unbalance between treatment groups. If the evidence is overwhelming, the sponsor and the DSMC will likely agree on the appropriate course of action to take. If there is a trend in one direction or the other, the decision may be delayed until further data are available for review; if so, the committee will very likely meet more frequently until the situation resolves.

Most trials continue to completion without intervention. However, it is reassuring to know that study subjects, who ultimately translate into all potential patients for a new treatment, have the additional safety protection or the opportunity for faster benefit of a clearly better treatment that are afforded when DSMCs are used in trials.


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